In recent years, in a mobile wireless communication terminal, a plurality of wireless systems are incorporated. In order to carry out service area detection (hereinafter referred to as area search processing) for each of the plurality of wireless systems, reduction in power consumption of the mobile wireless communication terminal is desired. As a method of reducing power consumption thereof, there is a method of reducing the power consumption by making the search period longer in a stepwise manner when the mobile wireless communication terminal is positioned out of the service area of the base station to lower the frequency of search, because the base station cannot be detected when the mobile wireless communication terminal is positioned out of the service area.
However, there is the problem that by the conventional method in which the search period is made longer, detection of the base station is delayed when the mobile wireless terminal device enters the service area, thereby impairing user convenience in some cases.
In the conventional mobile wireless terminal device, there is the problem that when the period of searching for the base station is made longer in order to reduce the power consumption, detection of an entrance of the device into the service area is delayed, thereby impairing the user convenience in some cases.